In many industries, modular steel containers have become a common and useful means for transporting various goods and materials. Such containers typically are mounted on flat bed trucks and trailers for overland shipment, placed on railway cars for rail shipment, loaded on the decks of freighters for overseas shipment and even placed in air craft for air shipment. For shipment of bulk commodities, plastic film liners have been developed for use in such containers which provide for the shipment of a large variety bulk materials without danger of contamination or spillage of the materials being transported. Along with the development and use of liners in modular shipping containers for handling bulk materials, there has developed the requirement to provide machinery for filling lined modular containers efficiently without causing any damage to the liners thereof. In the prior art, various bulk material loading methods have been used for filling such lined containers but with limited degrees of success.
An example of an existing method of loading a bulk material into a lined container is the use of a pneumatic conveying system. Such system has become popular in use because of its comparatively simple construction, essentially requiring a length of conduit and a supply of high velocity and volume of air, its capability of conveying material to the far end of a container and its ability to convey material relatively long distances to modular containers without contamination or spillage. However, such type of system has a number of disadvantages which limits its effectiveness in loading lined modular containers. Such disadvantages include the relatively high energy cost in producing a high volume and velocity air stream for conveying the materials, the risk of rupture of the liners within the containers caused by the impingement of material particles propelled at high speeds, resulting in material contamination or spillage, the risk of overpressurizing the container causing possible damage to the liner or the container, and the problem of handling large volumes of dust and air in the containers.
It thus has been found to be desirable to provide an improved system and method of transporting bulk materials and more specifically an improved system and method for loading bulk materials into lined shipping containers in which such containers are efficiently filled without rupturing or otherwise damaging the liner or the container.
The present generally provides for a container which may be loaded with a bulk material at a first geographical site, transported to a second geographical site by means of land, sea or aircraft and unloaded at such second site, and a bulk material loader located at the first geographical site. The container preferably is provided with a liner within the compartment thereof and an access opening communicable with the interior of the liner, in an end wall thereof, adjacent a top wall of the container. The loader comprises a mechanical type conveyor generally including a drive sprocket, a spaced driven sprocket and a rope assembly including a rope disposed along a circuitous path and reeved about such sprockets and a plurality of discs secured to and spaced along the rope driven at high speeds for creating a column of air and conveying bulk material in the conventional manner. The conveyor is provided with a cantilevered section including the driven sprocket, which is insertable through the access opening in the container end wall for conveying material into the container compartment. The driven sprocket in the cantilevered, insertable section of the conveyor is oriented with its axis of rotation disposed substantially vertically so that the sprocket may be positioned close to the upper end of the container compartment and displaced along the length of the compartment to tangentially disperse material carried by the rope assembly, throughout the compartment. The container end wall also is provided with a discharge opening at the lower end thereof to permit the discharge of material in the compartment at the final destination of the container simply by tilting the container to cause the gravity flow of material through the discharge opening.
The access opening in the container end wall may be disposed in the center of the end wall or adjacent a side wall of the container. In addition, the container end wall may be provided with a pair of access openings and the conveyor may be provided with a pair cantilevered sections insertable into such access openings. In such latter arrangement, it is contemplated that the rope assemblies of the two sections would be driven in opposite directions to provide a suitable dispersion pattern of the material injected into the container compartment.